KABUL, AFGHANISTAN
— Afghanistan's constitutional convention, scheduled to start Saturday, was supposed to be a break from the feuds of the past, a made-for-TV demonstration that the war-torn country had united around a blueprint for democracy.

Now a coalition of powerful guerrilla commanders is poised to wrest control of the proceedings and redraft the new Afghan constitution according to their own wishes.

Led by a broad array of religious parties from Afghanistan's many Islamic sects and ethnic groups, these mujahideen or "holy warriors" have set their sights on diluting the sweeping powers of President Hamid Karzai by pursuing a parliamentary system. It would be a setback for American officials who consider Mr. Karzai to be the best leader for the next Afghan government.

"If there is a parliamentary system, I will not be a candidate," he said. "If the loya jirga decides to bring a prime minister, let them do it."

To the dismay of the American government, the mujahideen have the numbers on their side. Of the 500 delegates selected during the past few weeks for Saturday's constitutional loya jirga, or grand council, more than 70 percent are associated with mujahideen parties, according to a survey by Agence France Presse. Among the remaining 30 percent, some are aligned with Karzai, while others are monarchists, who favor some official role for the elderly king.

"If [Karzai] doesn't follow the loya jirga, then there could be turmoil, political fighting. Karzai will only be making more opposition against his government," says Abdul Hafiz Mansoor, a senior official in the Jamiat Islami, an Islamist party that fought the Soviet occupation of Afghanistan during the 1980s.

While the Karzai government says it welcomes a full and frank discussion on the future constitution - and US diplomats say they anticipated opposition all along - this is clearly not the loya jirga that they wanted. Far from a 10-day rubber stamp of the present constitution draft, which gives sweeping powers to the presidency and makes few provisions for checks and balances on his power, the loya jirga could well turn into a heated affair that sets faction against faction and leaves the US-backed Afghan leader weaker than when he started. In addition, some insiders now predict that the process could drag out for many weeks, and even months.

The actual drafting of the constitution appears to have been a rather quiet affair. The constitutional commission, representing members of all ethnic groups, sects, and regional groups, spent the last nine months cobbling together a document largely based on the constitution of 1964.

When the draft was released a month ago, international reaction was warm and positive. Human rights groups hailed its protection for the rights of women and ethnic and religious minorities. Religious conservatives supported the provisions that declare Afghanistan an Islamic state.

The constitution draft has some other 21st-century touches. While guaranteeing the primacy of Islam, the draft constitution also protects freedom of religious practice. And the draft also would make school compulsory, both for boys and girls.

But underneath this shower of praise, there was an undercurrent of discontent. Former guerrilla commanders, now under pressure to disarm, worried that they would be shut out of the power game forever. And the seven religious parties that once struggled among themselves for control of Kabul - killing an estimated 50,000 people from 1992 to 1996 - now appear to be reuniting in order to remain a political force.

For the past two weeks, mujahideen leaders, including Defense Minister Mohammad Fahim, Yunis Qanooni, Abdul Rab Rasool Sayaaf, Kareem Khalili, and the late Ahmed Shah Masood's brother, Ahmed Wali, have been holding a series of meetings - often over dinner - to discuss strategy. Loya jirga delegates supportive of these mujahideen groups have been studying up and honing their arguments in favor of a parliamentary system.

"We have invited hundreds of delegates last night and had a large discussion on the issues," says Aqa Mohammad Nazari, a senior leader in Jamiat Islami. "The majority want a parliamentary system with a prime minister. People do not want a dictatorship. They do not want complete power to be in one man's hands, whether it's Karzai or somebody else."

The mujahideen have some unlikely allies in the drive for a parliamentary system. Those who have attended the meetings say that members of the monarchist party, the Movement for National Unity of Afghanistan, have also been discussing ways to rewrite the constitution and weaken the powers of the presidency.

Under the current draft, the president could sack officials and remove regional governors at will. While the draft allows for a legislative body, the president could encroach on its authority through decrees.

Western diplomats say privately that any move to weaken the president would make the Afghan government less effective. "It is only because Karzai has these powers that we're starting to see things getting done," says one senior US diplomat.

But publicly, US diplomats say that the very fact that it's possible to hold a constitutional convention to discuss these issues shows that Afghans have more freedom.

"The Afghans are discussing issues that they have not discussed ... during their past 5,000 year history," said US ambassador Zalmay Khalilzad, in a recent press gathering in Kabul. "They are debating it with freedom and with confidence."

Drafters of the constitution say that reaction to the draft thus far has been positive. "Everyone who reads this constitution is agreeing, not arguing," says Abdul Salam Azimi, deputy chairman of the constitutional commission.

While the mujahideen point to their overwhelming support of loya jirga delegates as evidence that they represent the true voice of the people, many Afghans themselves voice concerns that a prolonged power struggle could push the nation once again into violent factionalism.

A recent survey of 1,500 Afghans from various provinces by the aid group CARE showed that most Afghans are more interested in improvements in security and economic growth than in political loyalties. Asked what they would do first if they were president, 43 percent said they would improve security by beefing up police and disarming warlords. Forty percent said they would focus on job creation, health care, or education. Only 7 percent said they would focus on the balance of ethnic or tribal groups in the government.

Among ordinary Afghans, Safia Niazi is probably typical. Principal of a girls' high school in Kabul, she is neither satisfied with the present government nor happy with the savage history of infighting among the mujahideen. Instead, Ms. Niazi says she simply wants to see a country safe enough to send children to school.

"I've read this constitution, and it's very good for the people of Afghanistan," she says. "But we will see what the people of Afghanistan do with the constitution. Will they follow it or not?"

But while many Afghans blame the mujahideen for four years of civil war that destroyed the city of Kabul and ushered in the harsh Taliban regime, mujahideen officials themselves say they are ready to share power, and rule maturely.

"During the jihad [holy war] the Afghan people gave their own sons to the guerrilla leaders to fight the jihad, knowing they would be killed," says Nazari. "They trusted the mujahideen then, but now these people are called warlords. Why? We are the same people."